How to Make Cold Brew Tea
Use 8-10g of loose leaf per liter of cold filtered water, cover, and steep in the fridge at about 4°C (39°F). Strain after 4-6 hours for green and white tea or 8-12 hours for oolong and black tea, then keep it refrigerated and drink it within 2-3 days.
Cold brewing extracts tea with time instead of heat. Leaf sits in cold water for several hours, and the slow extraction pulls out sugars, amino acids such as L-theanine and aromatic compounds while leaving behind much of the catechins and caffeine that dissolve best in hot water. The result is a smooth, sweet cup with very little bitterness or astringency, even from teas that turn harsh when brewed hot. The method has a long history in Japan, where mizudashi sencha is made by steeping green tea in cold water, and in Taiwan, where cold-brewed oolong is sold in bottles at convenience stores. It became common in Western kitchens because it is hard to get wrong: there is no temperature to hit and the window for straining is measured in hours, not seconds. Almost every tea works. Japanese sencha and gyokuro become intensely savory and sweet. Taiwanese high mountain oolong and Oriental Beauty turn floral and honeyed. Darjeeling and Dian Hong make a clean iced black tea without the cloudiness that hot-brewed black tea develops when chilled. Jasmine green and white teas such as Bai Mu Dan are also good choices. Heavily roasted or smoky teas are less rewarding, since much of their character depends on heat.
Recipe
Teaware
- 1-liter glass pitcher or jar with lid
- Kitchen scale reading to 0.1g
- Fine-mesh strainer
- Filtered water
- Refrigerator
- Second pitcher or bottles for the strained tea
Steps
- 1
Weigh the leaf
Weigh 8-10g of loose-leaf tea for each liter of water. Use 8g for delicate greens and whites and 10g for oolong and black tea.
Cold brew needs about 3-4 times more leaf per ml than you might expect from hot brewing, because cold water extracts less.
- 2
Add leaf to the pitcher
Put the dry leaf in a clean 1-liter pitcher or jar.
Loose leaf is better than an infuser basket; the leaf needs room to unfurl to extract evenly.
- 3
Pour in cold water
Fill with 1000ml of cold filtered water and stir once so every leaf is wet.
Filtered water matters more here than in hot brewing, because chlorine flavor is not driven off by boiling.
- 4
Cover and refrigerate
Cover the pitcher and place it in the fridge at about 4°C (39°F).
Steep in the fridge rather than on the counter; it keeps the tea food-safe during a long steep.
- 5
Time the steep by tea type
Steep green and white tea for 4-6 hours, Japanese sencha for 3-4 hours, and oolong and black tea for 8-12 hours.
Taste at the short end of the range. Cold brew rarely turns bitter, but green tea can go grassy past 8 hours.
- 6
Strain the leaf out
Pour the tea through a fine-mesh strainer into a second clean pitcher or bottles and discard the leaf.
Press gently on the leaf in the strainer to recover the last 50-80ml of tea without forcing out bitter sediment.
- 7
Store and serve
Keep the strained tea covered in the fridge and drink it within 2-3 days. Serve straight, without ice, or over a few cubes if you want it colder.
Ice dilutes cold brew noticeably; if you like ice, brew at 10-12g per liter so it stays full-flavored.
Tips
- Rolled oolongs such as Tieguanyin and High Mountain Oolong can be cold brewed twice; give the second round 12 hours.
- For a sweeter green tea, steep sencha at 10g per liter for 3 hours; the result is rich in umami and low in bitterness.
- Cold-brewed black tea stays clear when chilled, unlike hot-brewed black tea, which clouds.
- Label the pitcher with the start time so you strain it on schedule.
- Add citrus peel or a few mint leaves only for the last hour of steeping so they do not overwhelm the tea.
Common Mistakes
- Using hot-brew quantities (2-3g per liter) — the tea tastes like flavored water; use 8-10g per liter.
- Leaving the leaf in for 24 hours or more — green tea turns flat and vegetal; strain on time.
- Steeping on the counter at room temperature — risks bacterial growth over many hours; steep in the fridge.
- Keeping strained tea for a week — flavor fades and it can spoil; drink within 2-3 days.
- Using tap water with heavy chlorine — the off flavor carries straight into the cup; use filtered water.